The present invention relates to controlling the feeding of casting powder into a mold for continuous casting.
It is common practice to feed a casting powder of the mold for continuous casting during casting thereof. The rate of feeding per unit time must bear a particulate relation to the casting speed and to the metal throughput so that the powder can fulfill its function which is the production of lubricating slag. Also, powder additives are used for additional metalurgical purposes. Thus, one should meter and control the feeding of casting to the mold.
Adding the powder poses the problem of dust development, which is an undesirable side effect, to be suppressed as much as possible. To achieve this, some of us have suggested to fluidize the casting powder so that, indeed, a controlled flow as far as the powder itself is concerned can be provided under conditions which minimize and even avoid dust development. (Ser. No. 025,581, filed Mar. 30, 1979.)
A problem exists with regard to the quantitative metering of the powder and the rate of application. German printed patent application No. 24,25,381 describes a control device for casting powder application operating in response to bath surface temperature. The surface temperature of the molten metal is, indeed, an indicator for the requisite amount of powder needed in any instant. Unfortunately, measuring the surface temperature of the bath of, e.g., molten steel is quite difficult on account of the extremely rugged operating conditions. There is a need for a reliable mode and manner to ascertain the surface temperature of the mold bath so that the casting powder feeding can reliably be controlled in accordance with the measured value.